You're looking for a fat .50 cal ammo can. It's big enough to hold a nice combination of items for both kids and adults (and even a few for dogs). Bring your trade items or trackables and help us keep this one fun for all ages! The logbook won't be filling up any time soon, so consider writing a little something about your journey for others to enjoy when they visit. This used to be the norm in the early days of this game, and I'd love to see the habit make a comeback.
While you're here, consider checking out the rest of Badger Prairie County Park. Depending on when you search, you may be able to watch planes from the nearby RC airfield while you're at ground zero. There is a nice series of hiking/biking trails throughout the park including a section of the Ice Age Trail. You can also find several other caches nearby, as well as a playground and a dog park. Have fun!